The present invention relates to a fake-finger determination device or the like suitable for recognizing a fake-finger.
In recent years, fingerprint authentication is attracting attention as one type of authentication system for identifying individuals. A fingerprint is unique in that it is different for every person, and that it does not change even with the lapse of time. Accordingly, it is said that fingerprint authentication is more reliable than the currently prevalent password authentication or the like. Meanwhile, with fingerprint authentication, it is necessary to prevent fraudulent acts of someone acquiring and forging the fingerprint of another person and using a fake-finger or the like to impersonate that person.
As a method of recognizing a fake-finger, for instance, proposed is a method of using a reed-shaped sweep-type sensor, causing the finger placed on a sensor to slide in two directions; namely, front and back (fingertip direction and finger base direction) at a constant speed, confirming whether the difference (that is, the deformation amount) between the two obtained fingerprint images falls within the normal range of the deformation amount that is obtained when a real finger of a human being is used, and thereby determining whether or not the finger to be recognized is a fake-finger (for example, refer to Patent Document 1).
Patent Document 1: Japanese Translation of PCT Application No. 2007-511845
Nevertheless, with the method disclosed in Patent Document 1, the test subject is required to perform two input operations (that is, operations of sliding one's finger in two directions; namely, front-and-back directions relative to the sweep-type sensor), and there is a problem in that this deteriorates the user-friendliness.
In addition, when using a sweep-type sensor, the test subject is required to slide one's finger at a constant speed. This causes variance such as individual differences in relation to the deformation of the fingerprint image, and the determination accuracy may deteriorate.